After much toiling, stress and a few choice expletives over the final boss (Valvur Ichabo you are a bad BAD man!) I have my 1000gs from this awesome game. I was stressing after it was a done deal for a good 30 minutes before the Owls of the Nest achievement unlocked and for a while thought I'd encountered a problem with the unlocking of it. Don't panic if (like me) when you return to Plumpet and view your save slots that the most recent save still shows as the same percentage as it did prior to the final boss. When I warped back to Stasis Chamber it also repeated the dialogue just before the boss battle - all of which convinced me that I had to re-do it as I was sure it hadn't unlocked - I was gutted (that's putting it mildly!!) as I said though 30 minutes or so later there it was - cheeeev - phewwww!!
With such extensive maps I'm hoping that this is an indication that we can expect some DLC to expand the game, does anyone know if that's going to happen?